The present invention relates to a device installed in an electrophotographic copier with a dry process developing unit for supplying a toner or like developer to the developing unit.
One of toner supply devices heretofore proposed for use with dry process electrophotographic copiers employs a cartridge which is held by a toner container and turned upside down to let the toner to fall by gravity into the toner container. In another type of prior art toner supply devices, a hollow cylindrical cartridge is formed with a slot and turned over within a toner container to supply the toner. In still another type of prior art toner supply devices, a cartridge with a generally L-shaped pipe attached thereto is arranged to supply a toner while being rotated about an axis thereof.
A drawback encountered with the first-mentioned type of toner supply device is that a substantial space for housing the cartridge is required in an upper portion of the developing unit in order to place the cartridge upside down and, accordingly, the device is inapplicable to a small-size copier which has a developing unit in an upper portion of its body. The second-mentioned cylindrical cartridge type device cannot have its slot widened beyond a certain limit because of the need for sealing, blocking tending to occur in the slot. The cylindrical cartridge, therefore, has to be sufficiently shaked before use. Further, the third-mentioned type of device using an L-shaped pipe requires the cartridge to be held face down resulting in a severe space requirement as in the case of the first-mentioned type. Additionally, this type of device with the L-shaped pipe fails to be fully unloaded and tends to smear the hands in the event of replacement.